I noticed how much volunteering was helping with my anxiety and stress, and there’s science to back it up.

There are horse barns in New York City. A lot of people don't realize this, but I'm lucky enough to have uncovered this secret through volunteering at a therapeutic riding program for children with disabilities. A couple of Sundays a month, I get up early, drink my coffee on the train to Forest Hills, and spend a few hours helping kids with their riding lessons.

I'm not saying all of this to get some kind of good Samaritan points. In fact, volunteering is one of the most self-serving things I do, because whenever I help out at the horse barn, my stress and anxiety levels noticeably drop. I feel calmer, more relaxed, and my mind is clear, often for the first time in weeks. It has quickly become one of the most reliable ways for me to de-stress—I've found it more effective than meditation, medication, or exercise.

It's generally understood that helping out others makes a person feel nice, but that experience goes beyond just the feel-good glow of altruism. Studies have found that helping others has tangible benefits, both mental and physical, from lowering your blood pressure to reducing feelings of depression. And research hasn't found any significant difference in the types of volunteering—any kind of helpful act can create benefits.

One of the horses waiting patiently for his rider. Image: Kaleigh Rogers/Motherboard

"Research has shown that there's evidence volunteer work promotes that psychological well being you're talking about," said Rodlescia Sneed, a public health research associate at Michigan State University who has studied the impacts of volunteering. "In my own work I've shown it's linked to improvements in factors like depressive symptoms, purpose in life, and feelings of optimism."

This is still an emerging field of study, so the underlying functions aren't fully understood yet. But we have a few clues, like research that has shown oxytocin (a neurotransmitter that regulates social interaction) spikes in some people who regularly volunteer, helping them to better manage stressful events. Sneed said there's also prevailing theories that volunteering is beneficial because it allows someone to focus on something else for awhile and may provide useful perspective—your problems don't seem as bad when you're working with people who don't have enough to eat, for example.

I wasn't anticipating these benefits when I began volunteering. I had volunteered in high school (a compulsory program, which have been shown to increase the likelihood that a teen will volunteer again later in life) and enjoyed it. There is just this general warm-fuzzy feeling you get from doing something you think is right. But I didn't expect the stress release and reduction in anxiety. If anything, I thought volunteering might make me more stressed, adding an extra obligation to my plate and eating up my down time.

But it had the opposite effect. When I finish a volunteering session, my muscles are more relaxed, as is my breathing. My mind is also not whirring with worry the way it usually does, and I feel energized to take on the rest of the day.

Sneed has led research on the physical health benefits of volunteering, finding that adults over 50 who volunteered at least 200 hours a year had a lower risk of hypertension. She told me there are a few reasons why pitching in can improve your health, and in populations over 50, it's easier to theorize the correlation, Sneed said.

"If you think about people who have gone through life transitions like retirement, becoming bereaved, or no longer having children in the home, they might not have social connections they once had," Sneed told me. "Doing volunteer work is a way to replenish those social ties."

Helping others is a natural high our brains are wired for.

It also promotes physical activity, Sneed said, even if it's just walking to the library to host children's story time.

But it goes beyond the act of volunteering. Altruism in many forms, from donating money to a worthy cause to just random acts of kindness, have been shown to light up the same reward centers of the brain associated with food and sex. Helping others is a natural high our brains are wired for.

The one exception: when doing good is your job. Though doing work you find meaningful ultimately contributes to a more lasting feeling of contentment, jobs where altruism are baked in—like health care and aid work—are often high stress environments commonly linked with poor mental health outcomes. So even if your job is to help people, you might benefit from some volunteering on the side.

When it comes to younger populations and the potential benefits of volunteering, particularly for those dealing with a lot of stress or mental health problems, Sneed told me there's not as much research. This surprised me, considering volunteering is a free, low-risk, simple tool that people could fold into their mental health care—why aren't doctors recommending this as much as any other lifestyle change, like exercise?

Sneed said there just hasn't been as much research done, but the subject area is growing.

"Given what we know about the links between volunteerism and psychological well-being, it would make a lot of sense to study the impact it might have on people dealing with mental health concerns," Sneed said. "There's lots of literature in general that shows providing support to other people is good for you. This is just one example."